The utility of blood glucose meters in biotechnological applications

Most methods used to measure glucose concentrations in biotechnological settings are labour-intensive and/or expensive. With this in mind we have investigated the possibility of employing blood glucose meters, the use of which has the benefit of being fast, convenient and inexpensive, for this purpose. Accu-Chek Advantage (Roche Diagnostics, Indianapolis, IN, U.S.A.) and Precision QID (Medisense, Abbott Laboratories, Indianapolis, IN, U.S.A.) meters were tested using glucose samples of known concentration, at pH 7.5 and 4.8. The Accu-Chek Advantage meter uses strips containing the enzyme glucose dehydrogenase. This meter showed a linear response for glucose concentrations between 0.50 and 6.0 g/litre, and the effect of pH was small. The Precision QID meter uses strips containing the enzyme glucose oxidase and is more sensitive to pH. The displayed glucose concentrations at low pH values were consistently lower than at higher pH values. At both pH values the response curve reached a plateau, which limited the effective range of this meter to a range of 0.30-2.5 g/litre. Unlike the Precision QID meter, the Accu-Chek Advantage meter also responded to xylose and arabinose. A synergistic effect of combining sugars was observed when a mixture of sugars consisting of glucose and arabinose, or glucose and xylose, was applied: the displayed concentrations were consistently higher than was expected on the basis of the individual calibration curves. The use of glucose meters is a fast and convenient alternative to existing methods and may be of particular use for screening purposes where a high degree of accuracy is not crucial. The choice of meter should depend on the application, and in this respect the pH, expected concentration range and the presence of other sugars are among the factors that should be considered.